Ventilating rotor construction



Nov. 23 1926.

P. SUTER VENTILATING ROTOR CONSTRUCTION Filed Jan. 25, 1926 Patented Nov. 23, 1926.

PHILIP? SUTE'R, OF BALDEN, SKVI'IZEELAND, ASSIGNOR TO AKTIENGESEIJLSCHAFT PATENT oFFicE.

BROWN BOVERI & CIR, OF BAIDEN, S'WITZERLAIID, A JOINT STOCK COMPANY OF SWITZERLAND.

VENTILATING ROTOR. CONSTRUCTION.

Application filed January 25, 1926, Serial No. 83,581, and in Germany January 30,1925.

This invention relates to construction of rotors for electrical machines, particularly induction motors. It has to do primarily with the assembly of the rotor laminations in a fashion such as to afford them desired cooling ventilation.

The general purpose of the invention 1s the provision of a construction which will afford the laminations and their associated windings the desired cooling ventilation, contribute to facility and economy of construction and preserve the integrity of the structure under trying operation.

Another object is the provision of such a construction particularly adapted to machines designed for high speeds.

Another object is to preserve the proper alignment of the winding slots of the laminations.

Other and further objects will be pointed out hereinafter, indicated in the appended claims, or obvious to one skilled in the art upon an understanding of the present disclosure.

In the accompanying drawing forming a part of this specification I'show one embodiment of the invention, but it is to be understood that the same is presented for illustrative purposes only and is not to be given any construction limiting the invention claimed, short of its true and most comprehensive scope in the art.

In the drawing,

Fig. 1 is a part transverse sectional view of a construction embodying the invention,

Fig. 2 is a sectional detail on line 22 of Fig. 1 and Fig. 3 is a sectional detail on line 3-3 of Fig. 1.

Referring to the drawing, let it be understood that the reference numeral 10 designates a portion of the spider of the rotor, which is suitably supported for rotation in a customary manner and affords an internal air circulating space S. In the spider are carried the rings 11, shrunk onto the spider while heated and further secured against shifting by the keys 12. These rings are continuous about the spider and are spaced apart, as .shown in Figs. 2 and 3, giving liberal space for radial movement of air between them. The spacing is preserved by the spacing pieces. 14:, which are secured to opposite sides of the alternate rings by the rivets 15. The rings are formed with the dove-tail projections 11, disposed in alignment longitudinally of the rotor, and the spacing pieces are likewise provided with of adjacent bundles being spaced apart, over the spaces between the associated rings 11,,

by suitable bosses or ribs 16*, so as to preserve air circulating spaces between them. These air spaces between bunches of laminations preferably. are somewhat narrower than the spaces between the rings, for a purpose mentioned hereinafter. At the ends of the rotor the laminations are retained by suitable clamping rings 17, drawn up by bolts 18. The laminations of the respective bunches preferably are of sufficient length to effect engagement, by means of their clovetail slots, with a plurality of the retaining ribs, and the laterally adjacent bunches are disposed in echelon or broken-joint relationship, as indicated by the line 6 in Fig. 1, showing the end of the next rearward bunch. The laminations are notched to provide the slots 16 for accommodation of the rotor windings, the arrangement of the notches being such that those of adjacent bunches align when the structure is assembled.

By virtue of the construction, therefore,

Thus continuous ribs of dove-- continuous passages are afforded radially between the rings and laminations and around the portions of the windings between the bunches of laminations, such passages ex tending from the space within the spider to the outer periphery of the rotor. Under the centrifugal action of the latter when running, continuous radial flow of air is maintained through these passages, the same exercising the desired cooling eifect on the rings, laminations and windings. By arranging the parts so that the spaces between juxtaposed bunches of laminations are slightly narrower than the aligning spaces between the rings, a condition is created which makes for an increasing velocity of air flow between the laminations with ade quate supply between the rings to avoid detrimental back pressure.

The construction is especially advantathe spaces between rings and windings traversing the laminations.

2. Rotor construction for elect lcal machines com 31181119 in combination a rotar H Y a l u suooort anoidinn an internal air OllCi'iltttlH l l l; c:

apart, spacing members carried by the rings, 1nd laminations retained on, the rings and aiming members.

3. Rotor construction for electrical machines, comprising, in. combination, a rotary v frame having an internal air space, rings embracing the smile and spaced apart to atford channels communicating with said air space, and lammations secured on the ringsand spaced apart in alignment with said channels.

l. Rotor construction for electrical ma- JPHCQ, rings 0 ribracing the same and spaced 1 chines comprising a rotary frame having an internal air space, rings encompassing the frame and spaced apart to afford air channels, spacing members bet-Ween rings, said rings and spacing members having aligning lamination retaining parts, and laminations retained by said parts.

'5. Rotor construction forv electrical machines comprising a rotary frame affording an internal air space, rings encircling the frame and spaced apart to aiiord air channels communicating with said space, bunches oi laminations on the rings in staggered relationship, the bunches being spaced apart across the channels, and spacing meniners engaging the rings and laminations.

(3. Rotor construction for electricaln'iachines, comprising, in combination, a rotor frame aiiording an air space, rings encircling the same and spaced apart to afford air channels, bunches oi? laminations retained on the rings and spaced apart to ati ord air passages aligning with said air channels, said air channels exceeding said air passages in width.

In testimony whereof I have hereunto subscribed my name at Zurich, Switzerland, on the 1.1 day oi January, A. D. 1926.

V PHILIP]? SUTER. 

